Malignant hypertension will be produced in the primate with the use of the Goldblatt technique. We will study and document clinically malignant hypertensive retinopathy and choriodopathy through serial stereo fundus photography and fluorescein angiography. The clinical lesions will be correlated histologically by light and electronmicroscopy and other special techniques such as trypsin digest preparation of the retina and choroid and enzamatic tracers. The latter technique is used to detect precise pathways of vessel leakage.